Method for forming liquid saturated towelette packets

ABSTRACT

Method for flattening, without wrinkling, sealed packets containing liquid-saturated towels and for evenly distributing the liquid within the towel component and detecting leaks in said packets.

United States Patent Field 1 Feb. 29, 1972 [54] METHOD FOR FORMINGLIQUID References Cited SATURATED TOWELETTE PACKETS UNITED-STATESPATENTS [72] 2,618,015 1 1/1952 Lloyd ..1o0/151 x [7 3] Assignee:Holland-Ramos Company, 1nc., 780,033 1/ 1905 Hachmann et a1. l00/1 18Piscataway, N-J- 2,675,053 4/1954 Clemens ..|00/l51 X Filed: Mar. 2 IOppenheim ..i0O/1 18 [21] P Primary Examine rlete1'FeldinanAttorney-Arthur B. Colvin [52] U.S.C|. ..100/35, 100/151, 53/124 A,

. 198/165 [57] ABSTRACT 51 I 1. Cl. .3301) 13 00 B301) 5 04 issi Fieldof Search ..100/151, 152/155, 154, 1 18, Metlwd flattening withwrinkling sealed Pad:ts

taining liquid-saturated towels and for evenly distributing the liquidwithin the towel component and detecting leaks in said packets.

3 Claims, 10 Drawing Figures PAIENIEUFEB29 I972 SHEET l or 4 I VIC/VI)R. DONALD G. FIELD ATTORNEY v PATENTEDFEB29 I972 SHEET 2 OF 4 ATTORNEYMETHOD FOR FORMING LIQUID SATURATEI) TOWELE'I'IE IPACKETS This inventionis in the field of manufacturing sealed packets containingliquid-saturated towels or the like.

In recent years, packets containing absorbent paper towels or the like,saturated with various liquid reagents, have found considerablecommercial acceptance. v

Commercial quantities of packets are typically supplied in boxes orcartons in which the packets are stacked or disposed in side-by-sideposition. In order that the space within the boxes or cartons be mostadvantageously employed, it is desirable that the packets bysubstantially flat.

in a typical packet, an absorbent paper towel is saturated with fluidreagent. Usually the towel is initially an elongated web which has beenfan-folded about longitudinally extending fold lines, the fan-folded webbeing thereafter transversely folded in advance of insertion into thepacket. In such structures, the areas immediately adjacent thetransverse fold line or lines contain a greater bulk of paper than theportions of the towel remote from the fold line so that the usual packetimmediately after fabrication displays a thicker end portion and athinner end portion.

In view of the greater bulk of material at the thicker end portion, whenthe packet is charged with its liquid contend immediately prior to finalsealing, there is a tendency toward concentration of the liquidcomponents in the areas of greater bulk, such that when the towel isremoved for use, it will contain areas of greater saturation and areasof lesser saturation.

The enclosing or outer skin of packets of the type described aretypically fabricated of a material which comprises a metallic foilintegrated in or coated with a heat-scalable plastic web. Unlike a pureplastic material, such composite foil-plastic has a relatively lowplastic memory factor, so that it will tend to take a permanent set orconfiguration if it is deformed.

Further, the foil-plastic composite will not shed wrinkles or creasespressed into the plastic.

Due in large to the wrinkle retaining and low plastic memory propertiesof the foil-plastic composite, conventional flattening methods have beenfound ineffective in their application to foil-plastic packets of thetype described. For instance, if a sealed packet is passed between apair of spaced roller members, the packet exhibits a marked tendency tocurl. Also, permanent wrinkles and creases are formed in a considerablepercentage of packets thus treated.

The present invention relates to a method for flattening sealed packetscontaining liquid-saturated towels or the like, and at the same timeeffecting a distribution of the liquid material within the body of thepacket, to assure essentially equal saturation of all portions of thetowel.

In accordance with the invention, filled packets are placed atop aplanar surface forming a moving portion of a conveyor assembly or thelike. The packets are advanced, preferably with the thicker end of thepacket (containing the transverse fold of towel) as the lead edge of thepacket beneath a second conveyor which is advancing at the same speed asthe packet supporting conveyor.

The second conveyor likewise includes a series of planar surfaces, whichsurfaces are led by the second conveyor in a converging path toward thepacket-supporting surfaces. The packets are sandwiched between theplanar surfaces of the first and second conveyors, and yielding pressureis applied to the packet through the surfaces. At least one suchsurface, nonnally the upper, is free to pivot relative to the othersurface, the other surface being slidingly supported in a predeterminedreference plane.

The aforementioned treatment results in an initial compression of thethickened end of the packet, driving fluid collected at such end intotrailing portions of the packet, to assure an equal distribution of thefluid. The packet is at the same time flattened by the application ofpressure, the pressure serving to outwardly expand the skin of thepacket to eliminate wrinkles and assure full distension of the skinportion.

Since there is no relative longitudinal movement between the packet andthe pressure-applying apparatus, there is no danger of forming newwrinkles or creases in the packet.

Likewise, since the packet is not passed across a curved surface, thereis no possibility that the packets will assume a set or curvature whichmight distort the packets from a flat configuration and thus preventtheir compact nesting within an enclosing box.

By subjecting the parts to pressure, any leak or weakness in the packetis readily detected by the fact that increments of the liquid would beexpressed from an imperfectly sealed envelope or packet.

Accordingly, it is an object of the invention to provide a method forflattening and distributing the liquid content of sealed packets.

It is a further object of the invention to provide a apparatus of thetype described which will accomplish the flattening and distributingeffects without distoring the packet or forming wrinkles in the packet.

In the accompanying drawings in which is shown one of various possibleembodiments of the several features of the invention:

FIG. 1 is a side elevational view of a packet-processing apparatus ofthe type described;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is an end elevational view of the packet-forming apparatus;

FIG. 4 is a magnified fragmentary view of the packet-compressingconveyor;

FIGS. 5a and 5b are longitudinal sectional views through packets,respectively before and after they have been subjected to the operationof the processing apparatus,

FIG. 6 is a magnified vertical section on the line 66 of FIG. 1,

FIG. 7 is an enlarged detail sectional view of a pickup nozzle takenalong line 7-7 of FIG. 1,

FIG. 8 is a top plan view of the article removal mechanism, and

FIG. 9 is a side elevational view taken along line 99 of FIG. 8.

Referring now to the drawings, there is shown in FIG. 1 a frame 10 onwhich the packet-processing apparatus 11 is mounted. To the right-handside, as viewed in FIG. 1, there is shown the terminal end 12 of thepacket-forming apparatus, the packets P being removed from the formingapparatus by a transfer assembly 13 which incorporate suction heads 14.The heads receive the packets P from the terminal end of the ap paratus12 and deposit them at the input area 15 of the packet-processingapparatus 11, which apparatus 11 is the subject of this invention.

As best seen in FIG. 2, the suction head assembly 14 includes dualsuction nozzles for simultaneously handling two packets P. The number ofpackets which are simultaneously processed is, of course, immaterial tothe invention hereof.

It will be appreciated that the transfer assembly 13 is driven insynchronism with the packet-fabricating apparatus 12 and the processingapparatus 11; By way of illustration, the processing apparatus ispowered from drive shaft 16 of the forming apparatus which shaft islinked in driving connection 7 with input sprocket 17 of the processingapparatus, as by a drive chain 18.

Packets P handled by the transfer assembly 13 are deposited on aconveyor assembly 19, the conveyor assembly including a pair of spacedparallel shafts 20, 21, joumaled in the frame 10. Each of the shafts 20,21 carries a pair of spaced sprockets 22, 22, 23, 23, respectively. Eachsprocket 22 is linked to a sprocket 23 by a driven chain 24. Shaft 20 iskeyed to the input drive sprocket 17, thus to drive the conveyor in thedirection of the arrow, Fig. 1.

The drive chains 24, 24 are spanned at regularly spaced intervals by aseries of packet support blocks 25. The support blocks 25 extend betweenthe chains, as best seen in FIG. I, the blocks being mounted to eachchain by a bracket member 26 fixed to a link of each of the chains 24,the outer end of the brackets 26 being centrally secured to the nuppoflblocks, It will be appreciated that by reason of this manner of cnnncction, the support blocks 25 will lie in a plane tangent to the point ofconnection of the brackets of the chains 24 as the blocks are advancedby the chains.

As the blocks 25 traverse the horizontal or upper flight of theirendless path, the undersurfaces of the blocks are slidingly supported onside rails 27, 27, forming a heightwise reference plane for the blocks.

From the foregoing, it will be seen that the support blocks 25 define aconveyor which advances packets along an essentially horizontal pathfrom the entrance of the apparatus to the removing mechanism 28.

Immediately above the conveyor assembly defined by the blocks 25, thereis disposed a second endless conveyor which will be referred to as acompression conveyor. The conveyor 29 includes spaced horizontal shafts30, 31 joumaled in the frame 10, which shafts respectively carry spacepairs of sprockets 32, 33. A pair of chains 34, 34 is extended betweenthe sprockets 32, 33, respectively, the chains carrying a series ofcompression blocks 35, 35 regularly spaced along the chains 34, tocorrespond with the spacing of the blocks 25 along chains 24. Thecompression blocks 35 include depending brackets 36 fixed to the linksof the chains 34. The brackets depend from substantially thelongitudinal central line of the blocks 35. It will be appreciated that,due primarily to the flexibility of the chains 34, the planardisposition of the undersurfaces 37 of the blocks 35 may be varied, thevariation being permitted by articulation of the chain.

Shaft 31 carrying sprockets 33 also carries sprocket 33 which isdrivingly connected as at X to shaft carrying to sprocket 23 the shaft20 also carrying the sprocket 17, so that the lower conveyor 19 andupper compression conveyor 29 are driven at the same linear speed withtheir adjacent runs moving in the same direction. It will be seen thatsince the upper conveyor 29 is shorter than the lower conveyor, acompression block (i.e., block 35', FIG. 1) will be converging toward asupport block of the lower conveyor, i.e., block 25' and that the twonoted blocks will thereafter be moved in parallel but spaced paths inthe juxtaposed areas of the two conveyors. It will be recalled that insaid juxtaposed areas the support blocks 25 are maintained in anessentially horizontal reference plane by the side rails 27 but, asnoted above, the compression blocks 35 are permitted a degree of bodilyupward and downward movement provided by the slack in the chains 34.

38 is a compression apparatus which functions to bring a yieldablepressure against the upper surfaces of the compression blocks 35 as theyare progressively scanned across the juxtaposed areas of the conveyors,also referred to as the compression zone S, see FIG. 1.

The compression assembly includes a generally U-shaped yoke 39 whichcarries a crossshaft 40. A spaced pair of compression rollers 41 isrotatably mounted on the shaft. The yoke is adjustably carried by a pairof support rods 41 joumaled for vertical movement in spaced bearingsleeves 42 formed in the frame, see FIGS. 1 and 6. Threaded tensionadjustment collars 43 are threaded over the rods 41, the upper surfacesof the collars 43 forming a support for the lowermost convolutions of apair of compression springs 44.

The upper ends of the compression springs bear against frame portionssurrounding the sleeves 42 the springs serving to press the collars andhence, the yoke and rollers, in a downward direction. It will beappreciated that the force exerted by the springs 44 is a function ofthe adjusted position of the collars 43 along the rods 41'.

Each of the upper ends of the rods 41 is fixed to a cage 45, the cages45 defining internal clearance areas 46. The upper ends of the cages 45are defined by horizontal follower bars 47. A cam rod 48 has itsopposite ends joumaled within spaced coaxial bearing portions 49, 50, itbeing understood that the axis of the bearings 49, 50 is offset from theaxis of the cam rod 48.

The undersurfaces of the follower bars 47 of the cages bear againstupper surfaces of the cam rod 48. The cam rod is made fast to camoperator lever 51.

From this arrangement it will be appreciated that rotation of the lever51 will rock the can rod about the pivot axis defined by bearings 49, 50and, depending upon the rotated position of the lever, will lift orlower the cages 45 by reason of the engagement of the rod with thefollower bars 47. Since, in all rotated positions of the lever 51, theclearance areas 46 within the cages provide considerable space beneaththe cam rod 48, it will be evident that the cages and the associatedyoke assembly carrying the rollers 41 may be forced upwardly against thecompression forces of springs 44 within the limiting confines of theclearance areas.

The lever 51 may be locked in any of a selected series of indexedposition by engaging retainer pin 52 carried by the lever in any one ofthe series of detent apertures 53 formed on a quadrant head 54surrounding the bearing 50. The pin 52 is normally pressed downwardlyinto the apertures 53 by a compression spring 55. A lift finger 56enables the pin to be withdrawn from an aperture to thus allow the leverto be pivoted to a selected different indexed position by releasing thefinger 56, whereupon the pin 52 will again enter the selected aperture.

As best seen in FIGS. 1 and 6, the lowermost surfaces of the rollers 41engage against the upper surfaces of compression blocks 35 as theseblocks scan compression area S.

The operation of the apparatus will be evident from the precedingdescription. Packets P are fed to a support block 25 by the transfermechanism 13. The blocks 25, carrying packets P are continuously movingfrom right to left as viewed in FIG. 1, carrying the packets beneath acompression block 35 of the upper or compression conveyor assembly. Thecompression block 35' of the compression conveyor 29 progressivelyconverges toward a synchronously moving block 25' of the conveyor 19,the packets preferably being arrayed on the blocks 25 in such mannerthat the thicker end of a packet P, i.e., the end having the transversefold, is in leading or downstream relation as respects the direction ofmovement. As the blocks 25' and 35 continue to advance from right toleft toward the compression station S, increasing pressure is exerted onthe packet or packets disposed between the aforesaid blocks, thepressure being first applied at the lead edge which, as noted, is thethicker portion of the packet.

The concentration of pressure at the lead edge is the result of theadditional thickness of the packet at such lead edge, and the fact that,due to the converging relation of the blocks 35 and 25, the lead edge ofsaid block 35' is inclined toward the support block 25 in the areaapproaching the compression zone S. As the juxtaposed blocks 25' and35', with a packet sandwiched therebetween, transverse the compressionzone S, the rollers 41 will scan across the upper surface of the block35'.

As previously noted, the lower block 25' is fixed in a predeterminedreference plane, the combined thickness of the packet and block servingto lift the roller against the pressure springs 44, such liftingmovement being accommodated by the clearance ares 46 within the cages45. The pressure which is exerted in the area S is a function of theadjustment of the collars 43 along the rods 41', enabling the processingapparatus to be readily adjusted to apply a range of compressive forces.Packets of different thicknesses may be readily accommodated bymodifying the adjusted position of the lever 51 in the manner previouslyset forth.

From the foregoing it will be understood that packets passing beyond thecompression zone S will have been flattened, the liquid componentswithin the said packets having been distributed substantially evenlywithin the confines of the packet.

In the event of a faulty seal, it will be evident that liquid will beexpressed from the defective packet as the same traverses thecompression zone S, thereby permitting improperly formed packets to bedetected and removed. Automatic detection apparatus may be employed,which apparatus may be made responsive either to expressed fluid orpreferably to the degree of upward movement of the rollers 41, in whichlatter instance the apparatus may also be used to detect under or overfilled packets.

Packets passing beyond the compression zone are withdrawn from theconveyor by the removal mechanism 28, which mechanism optionally butpreferably incorporates articulated suction heads 61 clearly shown inFIGS. 7 to 9. More particularly, each of the suction heads comprises ahollow stem 62 having a suction cup 63 secured to its lower end. Thestem 63 extends slidably through a bushing 64 mounted on the horizontalleg 65 of a support member 66 which has a vertical wall 67 rigidtherewith mounted for vertical movement of a carrier plate 68, slidablymounted for movement in a horizontal plane on guide rod 70.

The stem extends into the cavity 69 of a housing 71 to the upper end ofwhich a suction pipe 72 is connected. The downward movement of stem 62is limited by a collar 73 which abuts against the top of bushing 64.

The upper end of wall 67 carries a vertical arm 74 which is pivotallyconnected as at 75 to the end of the leg 76 of a bell crank lever 77,the free end of the other leg 78 of lever 77 being pivotally connectedas at 79 to a pitrnan 81 which is actuated by lever 82.

The lever 77 is pivoted to the carrier plate 68 as by being secured toone end of a rod 84, the other end of which is secured to one end of alever 85, the other end of which mounts a roller 86 riding in ahorizontal slot 87 in a wall 88, the end 89 of slot 87 being upwardlyinclined.

In operation of the removal mechanism, when the lever 82 is actuated torotate in a clockwise direction, referring to FIG. 9, the carrier plate68 will move to the right. When the roller 86 rides up the inclinedportion 89 of slot 87 this will cause lever 77 to pivot in acounterclockwise direction causing support member 66 to move downwardlyso that the suction cups 63 will be moved against the packets on blockat the discharge station. As a result of the suction applied to the cups63, the stem 62 and the packets P will be lifted slightly from the block25, leading space for the packets P carried by the next block 25 to movethereunder.

Movement of lever 82 in a counterclockwise direction will simultaneouslycause lever 77 to pivot in a clockwise direction as a result of themovement of roller 86 down inclined portion 89 so that the heads 61 willbe lifted further, and also cause carrier plate 68 to move to the leftso that the suction heads 61 will move to the position shown in fulllines in FIG. 9 over the discharge conveyor C. Thereupon, the suction isbroken and the packets P will be deposited on conveyor C and the cycleis repeated.

From the foregoing it will be evident that there is provided a novelprocessing apparatus for liquid filled, sealed packets whichautomatically flattens the packets to permit the compact array within anenclosure, while evenly distributing the liquid within the packet.

Unlike prior devices, the apparatus will not result in the formation ofwrinkles in the packets and, indeed, by reason of the development ofpressure of a hydraulic nature within the packets, effects a removal ofsuch wrinkles or unfilled portions as may exist in the packets prior tothe application of compressive forces thereto, resulting in theproduction of a more attractive and compact product.

I claim:

1. The method of removing wrinkles from and evenly distributing theliquid components within a sealed packet containing a liquid saturatedtowel or the like, said packet being formed of a foil-plastic compositehaving a low plastic memory factor, which comprises the steps ofsupporting a face of said packet on a first, substantially horizontal,planar, moving surface while linearly advancing said surface in apredeter mined direction, causing the other face of said packet to becontacted by a second planar surface converging toward and advancing atthe same linear speed as said packet, and thereafter urging said secondsurface toward said first surface under controlled pressure to compresssaid packet between said surfaces, thereby to develo internal hydraulicpressures within said packet su ficlent to mend the surface thereof andremove wrinkles therefrom and substantially evenly to distribute thefluid components within said packet while said packet continues to beadvanced between said surfaces.

2. The method of claim 1 wherein said second surface is free to tiltabout a horizontal axis disposed substantially coincident with thecenterline of said packet.

3. The method of claim 2 wherein said towel includes a thickened foldedge and said packet is oriented on said first surface in such mannerthat said first edge is in leading position.

1. The method of removing wrinkles from and evenly distributing theliquid components within a sealed packet containing a liquid saturatedtowel or the like, said packet being formed of a foilplastic compositehaving a low plastic memory factor, which comprises the steps ofsupporting a face of said packet on a first, substantially horizontal,planar, moving surface while linearly advancing said surface in apredetermined direction, causing the other face of said packet to becontacted by a second planar surface converging toward and advancing atthe same linear speed as said packet, and thereafter urging said secondsurface toward said first surface under controlled pressure to compresssaid packet between said surfaces, thereby to develop internal hydraulicpressures within said packet sufficient to distend the surface thereofand remove wrinkles therefrom and substantially evenly to distribute thefluid components within said packet while said packet continues to beadvanced between said surfaces.
 2. The method of claim 1 wherein saidsecond surface is free to tilt about a horizontal axis disposedsubstantially coincident with the centerline of said packet.
 3. Themethod of claim 2 wherein said towel includes a thickened fold edge andsaid packet is oriented on said first surface in such manner that saidfirst edge is in leading position.